Electric control system for actuating in a predetermined sequence a plurality of electro-magnetic relays

ABSTRACT

An electric control device for activating, according to a predetermined sequence, a plurality of electromagnetic relays, comprising an electronic program-switch connected to the relays by means of only three conductors only, two of which provide control signals and the other being a common return. Suitable change-over switches are included, so that the electric pulses alternatively sent through the program-switch onto the two control conductors, give rise to the sequential activation of said relays. The program-switch comprises: a transistor electronic circuit for generating controlling the frequency, duration and stability of the pulses, and a rotary relay, which when energized by a servo-relay, switches the pulses, alternatively, between the two control conductors. The programswitch also includes too a secondary electronic circuit for the control of the connection of the relays to the program-switch, and for adjusting the operation of the relays, each relay being connected to the return conductor through a change-over switch acted on by the preceding relay.

United States Patent Fontana ELECTRIC CONTROL SYSTEM FOR ACTUATING IN APREDETERMINED SEQUENCE A PLURALITY OF ELECTRO-MAGNETIC RELAYS Inventor:Ludovico Fontana, Bari, Italy Assignee: Technical Arco Establishment,

Sch'aan, Liechtenstein Filed: Dec. 29, 1972 Appl. No.: 319,701

[52] US. Cl. 317/140 [51] Int. Cl. H01h 47/14 [58] Field of Search317/137, 139, 140

[56] References Cited UNITED STATES PATENTS 3,200,303 8/1965 Maxwell317/139 3,521,130 7/l970 Davis et al.. 317/139 3,710,200 1/1973 Jones317/137 Primary Examiner-L. T. I-Iix Attorney, Agent, or FirmToren andMcGeady [5 7] ABSTRACT An electric control device for activating,according to a predetermined sequence, a plurality of electromagneticrelays, comprising an electronic program-switch connected to the relaysby means of only three conductors only, two of which provide controlsignals and the other being a common return. Suitable changeoverswitches are included, so that the electric pulses alternatively sentthrough the program-switch onto the two control conductors, give rise tothe sequential activation of said relays. The program-switch comprises:a transistor electronic circuit for generating controlling thefrequency, duration and stability of the pulses, and a rotary relay,which when energized by a servorelay, switches the pulses,alternatively, between the two control conductors. The program-switchalso includes too a secondary electronic circuit for the control of theconnection of the relays to the programswitch, and for adjusting theoperation of the relays, each relay being connected to the returnconductor through a change-over switch acted on by the preceding relay.

10 Claims, 5 Drawing Figures Pmmmumzmu 3795924 SHEET 1 BF 3 Fig. 7

PATENTED IAR l 2 I974 SHEET 3 0F 3 ELECTRIC CONTROL SYSTEM FOR ACTUATINGIN A PREDETERMINED SEQUENCE A PLURALITY OF ELECTRO-MAGNETIC RELAYS Thepresent invention relates to a device for acting sequentially activatinga plurality of electro-magnetic relays by means of three onlyconductors.

The control may be carried out either manually or automatically by meansof a suitable program-switch.

The electric circuit connecting the relays, the electric circuit of theprogram-switch, as well as a practical embodiment of the program-switchitself, are clearly shown in the accompanying drawings wherein:

FIG. 1 shows the circuit diagram of the relays to be controlled.

FIG. 2 shows the circuit of the program-switch; and

FIGS. 3, 4 and show thethree views of the program-switch.

FIG. 1 illustrates clearly the system resorted to for sequentiallyactivating relays I, II, III, IV, V and VI. Conductor n), constitutes acommon return for the relay control pulses. When an electric controlpulse is applied to conductor fd, only relay I activated. No other relaycan be energized inasmuch as only relay 1 is connected to the returnconductor n through its switch cl. When energized, relay 1 actuatesswitch cl which carries out the change-over of the return conductor n onthe switch 02, connecting in this manner, relay II to return conductorn. It is apparent that even in the case where the electric pulse remainsapplied to conductorfd, no other relay is energized. Upon switching thecontrol electric pulse from the conductorfd to the conductor fp, onlyrelay Il energized, as it which is then the only relay connected to thereturn conductor n.

In this case too, with the electric pulse remaining on conductor fp, noother relay is energized in that only relay II is connected to thereturn conductor n through its switch c2 and switch cl of relay I.

In view of the above, the switching operation, sequentially carried outby the relays, is apparent.

The switching rate is determined by the rate at which the electricpulses are alternately applied to the two conductors fd and fp. Thus,assuming the electric pulse is switched between conductors fd and fponce a second, one relay will be activated each second.

It is apparent too that if the electric pulses are simultaneouslyapplied to both conductorsfd andfp, the relays will be energized insequence automatically, at a rate determined only by the characteristictime of actuation of the individual relays.

From the above, it is apparent that by means of placing a suitableprogram-switch, switching in a manner described can be achievedautomatically or manually.

In the case of an automatic control, when the changing-over rate isestablished, activation of the relays takes place continually andautomatically. In the case of a hand control there a relay activatedevery time the voltage pulse is manually switched from one conductor tothe other.

The pr0gram-switch, illustrated in FIGS. 3, 4 and 5, comprises atransistor electronic circuit which serves to generate electric pulses,according to the rate desired.

Generally the duration of each pulse is about msec, whereas the timeinterval between a pulse and the following one can vary from a minimumvalue as of 200 msec to a few seconds, or more.

The electronic transistor circuit illustrated in FIGS. 3 to 5 is made upof a support member 1 of insulating material on which there is placed aprinted circuit which effects the connection of all the components whichmake up the circuit including; a rotary relay 2 (FIG. 4), a controlboard 3 (FIG. 3): and the connectors 25 and 26 for connecting the powersupply and the equipment fitted with the relays to be sequentiallycontrolled, respectively.

The operation is as follows: A unijunction transistor 4 (FIG. 2)generates current pulses according to a rate which is determined by thecapacity of a capacitor 5 and the resistance of a potentiometer 6.

The current pulses are amplified, adjusted and stabilized through thesuccessive electronic circuit and eventually they go to operate therelay 7, which, in turn, acts on the relay 9 when the change-over switch8) is located in the LAV. (work) position.

The energized relay 9, upon closing its contact 11, transmits a pulse tothe coil of the rotary relay 2 and to the coil of the blow countingrelay 10 whilst the contact 12 sends a pulse onto the central pole ofthe exchange contact 13 of the rotating relay 2.

The circuit shows clearly that depending on the position of the exchangecontact 13, the pulses are coupled onto conductorfd or onto conductorfp.Naturally, the rotary relay 2 advances a step forward when its coilreceives a pulse. Therefore at each pulse there is a change-over of thecontacts 13 and accordingly, there the pulse is switched from onecondutctor to the other. When the change-over switch 8 finds itself inthe position PR (Test), the pulse transmitted from the relay 7 energizesthe signal lamp 14 only.

The program-switch starts to operate by shifting of the switch 15 to theON position. In case switch 17 is positioned in the position AUT(AUTOMATIC), the electronic circuit will control relay 7 and the rate ofthe pulses will be monitored by the flashing of the signal lamp 14. Therate of the pulses may be modified by means of knob 16, (FIG. 3) whichcontrols potentiometer 6. If the switch 17 is positioned in the positionMANUALE (MANUAL), the signal lamp will be lit every time the push-button18) is acted on, inasmuch as each actuation of the push-buttoncorresponds to a pulse.

The rotary relay 2 is furthermore fitted with two contacts 19 and 20which serve to position it always in the same starting position. Indeedwhen the switch 15 is in the position SPENTO" (PUT OUT) the power supplyis connected to the coil of the rotary relay 2 through the two contactsmentioned above. Since the contact 20 is a cam contact, it is apparentthat in a well defined position the contact opens and the coil of therotary relay 2 is de-energized, producing the start positioning.

Shifting the switch 19) into the position SBLOCCO (RELEASE) pulses aresimultaneously applied to the two conductorsfd andfp, activating therelays I to VI at their free-running frequency.

The program-switch may be furthermore provided with a second electroniccircuit which is also equipped with transistors to signal of the factthat the electric connection to the relay group to be acted on has takenplace (this is material in the case said group is accommodated in amovable equipment with regard to the program-switch) and the actuationof all relays has occurred. Indeed in the case where the apparatus isnot connected to the program-switch, the resistance of the twoconductors fd and fp with respect to the return conductor n is veryhigh, and no current flows into the four transistors 21, and transistor24, and accordingly, neither the red signal lamp 22 nor green signallamp 23 will light.

In the case where that the apparatus is connected to the program-switch,the electric resistance of one of the two conductors fd or fp withregard to the return conductor n is equal to the coil resistance of arelay of the apparatus. In this case, current'flows into the fourtransistors 21 and the transistor 24, and both signal lamps 22 and 23light. In the case where the apparatus is connected to theprogram-switch and all the relays of the apparatus have functioned,there will be extant an electric resistance between one of the twoconductors fd or fp and the return conductor n determined by theresistance rl. Because of this resistance, the current circulating intothe transistors 21 is not enough to light the red signal lamp 22.However the current, suitably amplified by the transistor 24, will lightthe green signal lamp 23.

What I claim is:

1. An electronic control device for activating a plurality of relays ina predetermined sequence, comprising:

a program switch connected to said relays by means of only threeconductors, two of which couple control pulses to said relays, and theother of which provides a common return;

said program switch including:

a transistor circuit for generating and controlling the frequency,duration and stability of a train of pulses;

a rotary relay for alternately coupling said pulses to one or the otherof said two conductors;

means, including a servo-relay, for coupling said transistor circuit tosaid rotary relay;

means, including a secondary electronic circuit, for controlling theconnection of said relays to said program switch and for adjusting thefunction of said relays;

and means associated with each relay for activating the next relay insaid sequence.

2. A control device, as claimed in claim 1, characterized in that thelast relay in said sequence of the apparatus acts upon a change-overswitch which inserts into the common return conductor a resistor fit tocontrol a transistor in said secondary circuit which signals the end ofthe sequence.

3. A control device, as claimed in claim 1, characterized in that theprogram-switch includes means for varying the frequency of said pulsetrain.

4. A device as claimed in claim 6 characterized in that the rotary relayof the program-switch comprises two auxiliary electric contacts placedin such a manner that the start pulse, transmitted from theprogramswitch is always coupled onto the same control conductor.

5. A control device as claimed in claim 6, characterized in that theprogram-switch includes means having an electronic circuit forsignalling whether the relays are connected to the program-switch andwhether the sequence has ended.

6. A control system for successively actuating a plurality ofelectromagnetic relays, comprising an array of relays, a programswitching circuit for generating control pulses, three and only threeconductors connecting said switching circuit to said relays, two of saidconductors coupling the control pulses from said switching circuit tosaid relays, the third conductor serving as a common return, each ofsaid relays having transfer switch means for successively connectingeach of said relays to said return conductor, said switching circuitgenerating and stabilizing and transmitting a train of control pulses toone or both of said two conductors so that successive control pulsesactivate a different one of said relays, said switching circuitincluding means for monitoring the connection between said switchingcircuit and said relays.

7. The control system as in claim 6, further comprising a resistor and alamp, the transfer switch means of the last of the successively actuatedrelays connecting said resistor to said return conductor and causingsaid lamp to be illuminated.

8. The control system as in claim 6, wherein said program switchingcircuit includes means for varying the pulse rate of said control pulsetrain.

9. The system as in claim 6, wherein said program switch includes meansfor alternately applying control pulses to one or the other of the twoconductors.

10. The system as in claim 6, wherein said program switch includes meansfor monitoring the operation of said relays and for indicating thatproper operation of said relays has taken place.

v UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated March 12,1974 Patent No. 3 r 79 6', 924

Inventor(s) LlldOViCO Fontana It'is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the heading of the patent, insert Foreign Application Priority DataJanuary 28, 1972 Italy ..2lO5-A/72 Signed and sealed this 13th day ofAu'gnst 197A.

(SEAL) Attest:

MCCOY M. GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents U5C OMM-DC 60376-P69 w u.s. GOVERNMENT PRINTING OFFICE: I9690-365-334.

FORM Po-105o (10-69) UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3 r 9 924 Dated March 12 1974 Inventor(s) LudovicoFontana Itis certified that error appears in the above-identified patentand that saidLetters Patent are hereby corrected as shown below:

In the heading of the patent, insert -[30] Foreign Application PriorityData January '28, 1972 Italy.. ..2l05A/72-- Si g ned and sealed this13th day of Augilst 1971+,

(SEAL) Attest:

MCCOY M. GIBSON, JR. c. MARSHALL DANN Attesting Officer Commissioner ofPatents USCQMM-DC 60376-P69 UAS, GOVERNMENI PRINTING OFFICE I9690-366-334.

FORM PO-105O (10-69)

1. An electronic control device for activating a plurality of relays ina predetermined sequence, comprising: a program switch connected to saidrelays by means of only three conductors, two of which couple controlpulses to said relays, and the other of which provides a common return;said program switch including: a transistor circuit for generating andcontrolling the frequency, duration and stability of a train of pulses;a rotary relay for alternately coupling said pulses to one or the otherof said two conductors; means, including a servo-relay, for couplingsaid transistor circuit to said rotary relay; means, including asecondary electronic circuit, for controlling the connection of saidrelays to said program switch and for adjusting the function of saidrelays; and means associated with each relay for activating the nextrelay in said sequence.
 2. A control device, as claimed in claim 1,characterized in that the last relay in said sequence of the apparatusacts upon a change-over switch which inserts into the common returnconductor a resistor fit to control a transistor in said secondarycircuit which signals the end of the sequence.
 3. A control device, asclaimed in claim 1, characterized in that the program-switch includesmeans for varying the frequency of said pulse train.
 4. A device asclaimed in claim 6 characterized in that the rotary relay of theprogram-switch comprises two auxiliary electric contacts placed in sucha manner that the start pulse, transmitted from the program-switch isalways coupled onto the same control conductor.
 5. A control device asclaimed in claim 6, characterized in that the program-switch includesmeans having an electronic circuit for signalling whether the relays areconnected to the program-switch and whether the sequence has ended.
 6. Acontrol system for successively actuating a plurality of electromagneticrelays, comprising an array of relays, a program switching circuit forgenerating control pulses, three and only three conductors connectingsaid switching circuit to said relays, two of said conductors couplingthe control pulses from said switching circuit to said relays, the thirdconductor serving as a common return, each of said relays havingtransfer switch means for successively connecting each of said relays tosaid return conductor, said switching circuit generating and stabilizingand transmitting a train of control pulses to one or both of said twoconductors so that successive control pulses activate a different one ofsaid relays, said switching circuit including means for monitoring theconnection between said switching circuit and said relays.
 7. Thecontrol system as in claim 6, further comprising a resistor and a lamp,the transfer switch means of the last of the successively actuatedrelays connecting said resistor to said return conductor and causingsaid lamp to be illuminated.
 8. The control system as in claim 6,wherein said program switching circuit includes means for varying thepulse rate of said control pulse train.
 9. The system as in claim 6,wherein said program switch includes means for alternately applyingcontrol pulses to one or the other of the two conductors.
 10. The systemas in claim 6, wherein said program switch includes means for monitoringthe operation of said relays and for indicating that proper operation ofsaid relays has taken place.